Got a quick question about oil pressure. My brother has 1999 Dodge Ram 1500 with the 5.9. It has 230k miles and nothing has ever been done to the engine. We know it burns a quart of oil about every 1000 miles. Lately, we are having a little issue with the oil pressure. When he first starts the truck the oil pressure is fine. About 40-60. Once the truck is warm and he comes to a stop the oil pressure will sometimes drop to 0. It either immdeiately comes right back up to 40 or when he starts going again it will.

Anybody have an idea of what this could be??

 

A common problem. Could be oil pressure sending unit on passenger side of the dist., or most likely the OEM pressure gauge. Most of them are known to be crap. Get a mechanical gauge, hook it up and see what's really going on. A cheap gauge can be had at any place that sells well water pump supplies. Auto parts stores have them for more.

 

Agreed. Start by replacing the sender. I have seen this cause the same issue a lot, and you're chances of solving the problem is good.

As far as burning oil, your plenum gasket is probably blown, and that plate on the bottom side of the intake is not properly sealed. If that were the case, oil would be sucked up into the bottom side of the intake, and distributed with the fuel and air as it's sucked down into the cylinder chambers.

Remove the air hat, and the 4 bolts that hold the TB down. You should be able to move it enough out of the way to peer down into the intake with a flashlight. If you see oil pooled on top of that steel plate, the gasket is blown. If it's dry and fairly clean...your issue may be elsewhere.

 

Thanks for the replies guys. Where would I hook the mechanical gauge up that I will buy?

And I am pretty sure his plenum is blown. We will give that a check as well.

 

Might be easier to change the sender before trying a mechanical gauge. The sender is cheap.

 

Does the engine start ticking when the pressure shows 0?